The first time I played Super Mario World I didn't think it was different as 3 was to 1, 2, and 2. It just seemed like it was a worse Super Mario Bros. 3 with nice music, graphics, yoshi, some new gameplay mechanics, and I didn't find it difficult until the game got really close to the end.

Also saying Super Mario Allstars is cheating, that's like saying the best Namco game was Namco collection.

As for 64. Super Mario 64 was great for the time, but compared to its 2D counterparts it doesn't stand the test of time. There are better 3d platformers now, it just seems too basic for today's standards.